THE BIOSYNTHESIS OF FURANONES IN STRAWBERRY: ARE THE PLANT CELLS ALL ALONE?

摘要

The facultative methylotrophic bacterium Methylobacterium extorquens has been isolated from strawberry callus cultures and its role in the biosynthesis of strawberry flavor (2,5-dimethyl-4-hydroxy-2H-furan-3-one or furaneol~R) has been studied. The microorganism has been cultivated with 1,2-propanediol - a substrate that exists in strawberries - and methanol and 7 days later 2-hydroxypropanal (lactaldehyde) was detected as the DNP-derivative. This result in conjunction with the observation that strawberry cells can biosynthesize furaneol from lactaldehyde is discussed. We propose a symbiotic relationship between the bacteria and the strawberry cells: the strawberry cells provide a niche for the bacteria whereas the bacteria oxidize 1,2-propanediol to lactaldehyde; the latter is utilized by the plant cells in flavor biosynthesis.